1. Field of the Invention
The present general inventive concept relates to a heater, and more particularly, to a heater for an inkjet printhead, and a method of manufacturing the heater.
2. Description of the Related Art
Inkjet printheads are devices that eject ink droplets onto desired positions of a recording medium to form an image of a predetermined color. Inkjet printheads are categorized into two types of printheads according to the ink ejection mechanism thereof. The first type is a thermal inkjet printhead that ejects ink droplets due to an expansion force of bubbles generated in ink by thermal energy. The other type is a piezoelectric inkjet printhead that ejects ink droplets due to pressure applied to ink due to deformation of a piezoelectric body.
The ink droplet ejection mechanism of a thermal inkjet printhead will now be explained in detail. When a pulse current is supplied to a heater including a heating resistor, the heater generates heat and ink near the heater is rapidly heated up to approximately 300° C., thereby boiling the ink. Accordingly, ink bubbles are generated by ink evaporation, and the generated bubbles expand to exert pressure on the ink filled in an ink chamber. As a result, ink around a corresponding nozzle is ejected from the ink chamber in the form of droplets.
A driving system in an inkjet printer transmits a driving signal to a heater through a flexible printed circuit board (FPCB), a pad, a logic circuit unit, a power transistor, and wires, in order to drive an inkjet printhead. If a resistance of the heater is increased, a ratio of the resistance of the heater to a total resistance is increased, thereby improving energy efficiency. Since the heater can also be driven by a high voltage, a time required to drive the heater is reduced, thereby increasing a number of heaters that can be driven in a given period of time and improving a performance of the inkjet printhead. Accordingly, there are demands for developing a heater material that has a high resistance and a high reliability.